Automatic clutch



April 20, 1937. 7 c R ROCHE 2,077,956

AUTOMATIC CLUTCH Filed Oct. 5', 1951 1 2 Sheets-Sheet 1 I 74 "WIHHI 77 0 Z8 fir 1 m4 M April 20, 1937. C. R. ROCHE 2,077,956

AUTOMATIC CLUTCH Filed Oct. 5, 1951 2 Sheets-Sheet 2 [M/E/I TOZZ I 64 A ro/we. @0095,

4r TORNE x Patented Apr. 20, 1937 UNITED STATES AUTOMATIC CLUTCH Clifton R. Roche, Los Angeles, Calif., assignor to Bendix Products Corporation, South a corporation of Indiana Application October 5,

17 Claims.

My invention relates, to a clutch-operating device for use in automotive vehicles which operates automatically in response to predetermined pressure conditions within the intake manifold of the engine employed in the vehicle.

It is characteristic of internal combustion engine s, such as employed in automobiles, that when the carburetor valve thereof is moved toward closedposition, the condition of vacuum within the intake manifold of the engine increases and that any movement of the carburetor valve toward fully open position to feed more fuel to the engine results in'a reduction of the vacuum in the intake manifold, with a result that the pressure within the manifold increases. My invention utilizes in itsoperation this change in pres' sure in the intake manifold and constitutes an improvement over the device of a similar char.- acter shown in my pending application Serial No. 517,862, filed February 24, 1931, for Free-wheeling apparatus and clutch control.

The device shown in my prior application includes va cylinder with a piston working therein and means for attaching the piston to the clutchoperating lever of an automotive vehicle. Connected to the intake manifold of the engine is a valve normally held in closed position by a spring to open the clutch of the automobile. It will be seen that in such a device the clutch of the automobile is automatically held in open position Whenever the vacuum in the intake manifold is relatively high, thus making it possible to shift gears or to throw out the clutch for freewheeling purposes without the foot operation of the clutch pedal of the automobile.

In my prior invention the clutch-operating de vice is in communication with the intake manifold of the engine only during such time that the control valve moves into position for producing a clutch-opening actuation of the device.

When the clutch is engaged and the vehicle is being operated in a normal mannerthe cylinder of the clutch-operating device is open to atmospheric pressure. The result of this condition is Bend, Ind.,

1931, Serial No. 566,851

that before the piston can be moved 'in the cyl inder by suction from the intake manifold, the suction must first evacuate from the cylinder the air existing. therein under atmospheric pressure.

It is an object of my present invention to provide a clutch-operating device of the vacuum suspended type which operates solely in response to variations in pressure within the intake manifold of the automobile engine and is controlled entirely by the partial vacuum within the intake manifold, being above or below a predetermined value, and therefore requires no connection to or control by control pedals of the automobile and will operate without necessity of fully closing the throttle valve leading into the engine intake. As an example, the vacuum builds up in the engine intake manifold when the throttle valve starts to close and actuates the clutch-operating device in response to the increase in the partial vacuum within the intake manifold considerably before the throttle completely closes, thereby giving a very rapid action to the device and causing the clutch to be opened before the closing of the carburetor valve can result in a slowing down of the engine to the extent that the engine then u acts as a brake on the forward movement of the vehicle. This action of my device avoids all engine jerk 0n the forward operation of the car due to a rapid slowing down of the engine before the clutch is engaged. In my new device it is the degree of vacuum that controls its operation and not the degree of throttle opening.

It is an object of my present invention to provide a vacuum suspended type of clutch-operating device, one of the major characteristics of such a device being that the operating cylinder is continuously in open communication with the intake manifold so that a condition of partial vacuum continuously exists therein, thereby producing an actuating mechanism capable of quick response to a change in vacuum within the intake manifold of the engine.

It is a further object of the invention to provide a'device of-the above character having a pair of vacuum-actuated members operating on opposite sides of a movable member, these vacuum-actuated members being both connected to the intake manifold of the engine during the operation of the engine to propel the vehicle. During such time the clutch-operating device is inactive owing to the fact -that both of the vacuum members are in .communication with the intake manifold and the forces exerted thereby on'the clutch-moving member are balanced. It is a feature of the invention to provide a valve which produces operation of the clutch-operating device by cutting off from communication with the intake manifold one of the vacuumactuated members so that vacuum from the intake manifold may be exerted in one of the vacuum-actuated members to cause movement of the movable part which is attached to the clutchoperating mechanism of the automobile.

A further object of the invention is to provide in such a device a valve adapted to open one of the vacuum-actuated members to the atmospheric pressure so that the other.of the vacuumactuated members may by'suction produced and in direct connection with the intake manifold of the engine, cause movement of the movable part which connects to the clutch-operating mechanism of the automobile.

It is a further object of the invention to provide a device of the above character having a simple and effective means for controlling the closing movement of the clutch-operating part in accordance with the degree of manifold vacuum of the internal combustion engine. With such a construction the clutch of the automobile will beengaged in a minimum time; yet without grabbing or jerking due to an abrupt and forcible engagement' of the friction elements of the clutch.

'It is a further object of the invention to provide in a device of the above character a vacuumoperated clutch-actuating means having a control valve which operates automatically in response to predetermined conditions. of vacuum within the intake of the automobile engine, thereby avoiding need for external valve-operating parts connected with other control levers of the automobile.

A further object of the invention isto provide Further objects and advantagesof the inven tion will be made evident throughout the-following part of the specification. r

Referring to the drawings which are for illustrative purposes only,

Fig. 1 is a schematic elevational View showin the operating elements of an automobile and the manner in which the clutch-operating device is employed.

Fig. 2 is an enlarged view of the front end of the clutch-operating device vertically sectioned on the plane 2--2 of Fig. 1.

Fig. 3 is a section taken-on a plane indicated by the line 3-3 of Fig. 2, this view omitting the movable valve element and the movable parts associated therewith. 1

Fig. 4 is a fragmentary section on a plane represented by the line 4--4 of Fig. 2.

Fig. 5 is a diagrammatic view showing the control valve in the position it assumes when a condition of low vacuum exists in the intake manifold of an engine to which it is attached.

Fig. 6 is a view of a character similar to Fig. 5 showingthe valve in clutch-operating position to which it moves in response to high relative vacuum of the intake manifold.

Fig. 7 is a fragmentary vertical cross-section showing a preferred manner of connecting the clutch-operating device to the intake manifold at a point adjacent the plane of the carburetor valve in closed position, whereby a minimum opening of the carburetor valve will effect adrop in vacuum condition within the clutch-operating device.

Referring to the schematic view of Fig. 1,'I show an automobile engine having an intake manifold which shall be hereinafter referred to as the intake |2,'a carburetor |3 having a butter- I1 adapted to selectively connect the engine with a drive shaft l8 extending rearwardly to a differential, 'not shown. The transmission I! includes a clutch of the common type adapted to be engaged by'spring pressure and to be disengaged by inward movement of a, clutch pedal 2|] which is secured to a horizontal shaft 2| extending from the transmission I'I. Extending downwardly from the shaft 2| I show a lever 22 which may or may not be formed integrally with the clutch pedal 20. A spring 23 normally exerts a tension tending to operate the clutch pedal in a clockwise direction or toward the position it assumes when the clutch is engaged.

In Fig. 1 I show a preferred form of my clutchoperating device 24 which for'purpose of convenience I prefer to connect between the downwardly extending lever 22 and a cross member 25 forming part of the chassis 26 of the auto- I,

movable member therein consisting of a piston which in its fully rightward position engages a rubber stop orbumper 29 in the end wall of the cylinder 26. A space 3| within the cylinder 26 to the right of, the piston 3|] constitutes a primary vacuum-actuated means for moving the piston 30 in rightward or clutch-disengaging position, and a space 32 within the cylinder 26 to -the left of the piston30 constitutes a vacuumactuated means which produce'sforces tending to move the piston 30 in leftward direction when connected with a source of suction such as the intake I2 of the engine The piston 30 I show simply as a circle disc 33 having a cup-leather 34 mounted on the leftward face thereof. Extending leftwardly from the piston is a piston rod 35 which extends through a bore 36 formed in an axial wall 31 of the head, 2]. Threaded into the outer end of the piston rod 35 is an adjustable member 38 having an eye 39 in its outer end whereby it may be connected by means of a link 40 to the lower end of the'lever 22. The cylinder 26 has a boss 4| projecting rightwardly therefrom and a screw 42 isthreaded into the boss 4|, this screw 42 having an eye 43 engaging an eye-bolt 44 secured to the cross member 25.

A feature of my invention is the provision of a control valve 45 in close proximity to the vacuumactuated means 3| and. 32 so that the passages from the valve 45 to the actuating means may be as short as possible; thereby contributing to quick response of the device. The valve 45 con.-

sists of a cylindrical valve housing 46, preferably .75

integrally formed on the front of the head 21, and a movable valve element 41 in the valve housing 46, this valve element being shown in Fig. 2 in raised position. As clearly shown in Figs. 2 and 3, the movable valve element 41 consists of a cylindrical body having an open upper end and a wall 48 closing its lower end. Between the upper and lower ends of the valve element 47 is a circumferential groove or space 56. In the upper portion of the housing 46 is an annular suction space 5| which surrounds the upper portion of the valve element 41, and as shown in Fig. 3 has a threaded suction inlet opening 52 from which a conduit 53 extends to the intake I2 of the engine II, as shown in Fig. 1. Below the suction space 5|, and separated therefrom by an inwardly projecting annular wall 55, is

an annular space 56 from. which a passage 5'! extends outwardly across the face of the head 21 as shown in Fig. 2. The'leftward end of the passage 51- communicates with a passage 58 which extends back along the exterior of the cylinder 26 and opens into the extreme rear end of the cylinder 26, or, in other words, into the space 3|. space 56, and separated therefrom by an inwardly projecting annular wall 66, is an annular space 6|. The annular space 5| connects with the bore 36 of the axial wall 31 through which the piston rod 35 extends through an opening or passage 62, and in the same vertical plane as the open-.

ing 62 the outer end 63 of a passage64 communicates with the bore 36, the inner. end 65 of the passage 64 communicating with the space 32 within the cylinder 26 to the left of the piston 36.

Referring to Figs. 2 and. 4 a by-pass passage 61 connects between the annular space 6| and the space 32 within the cylinder 26, this by-pass 6'! consisting of a passage 68 extending leftwardly from the annular space 6| and a smaller passage 16 extending downwardly from the passage 68 to 'the space 32-within the cylinder 26. For controlling the flow through the by-pass passage 61 -I provide a valve II in adjustable relationship to the upper end of the passage I6.

In the valvehousing 46 below the annula space 6| and separated therefrom by a wall 13 is an annular space I4 which communicates with the space 32 through a relatively short opening or passage 15 extending through the wall of the head 21. In the lower end of the valve housing 46 an annular. rubber bumper 16 is held in position by means of an angle clip ll which may be secured to the head 21 by a screw I8. The upper end of the valve housing 46 consists of an end wall having an axial bore 8| through which a control rod 82 extends. 82 has a ring flange 83 thereon, this ring flange. being prevented from upward movement on the rod 82 by a spring ring 84 which rests in an annular groove 85 in the rod ,82. The spring ring 84 by engagement with the inner face of the end wall 86 of the housing 46 prevents removal of the rod 82 from the housing in upward direction. The valve element 41 is normally held in downward position by a spring 8'I-which surrounds the lower portion of the rod 82 and extends between the ring flange 83 and the end wall 48 of the valve element 41. varying the tension in the spring 81 I provide means for moving the rod 82 and the ring flange 83 downwardly from the position shown in Fig.

2, such means consisting of a lever 88 pivoted In the housing 46 below the annular The control rod Forthe purpose of on a pin 89 and having its rearward portion 9| adapted to be moved across a ratchet plate 92 by means of a wire 93 which is carried through a tube 94 to a handle 95 mounted on the steering post 96 of the automobile so as to be convenient to the driver of the automobile. The lower end of the wire 93 may be secured to the lower end 9| of the lever 88 by means of a set-screw 91 which is threaded into a body 98 on the lower end 9|. The ratchet plate 92 has notches or serrations I66 therein and is secured to the head 21 by means of screws I6I. Integrally formed with the ratchet plate 92 is an upwardly extending bracket I 62 providing a securing means I63 for the lower end of the tube 94 through which the wire 93 extends. By pulling upwardly on the wire 93, by use of the handle 85, the lever 88 may be swung in anti-clockwise direction so that its inner end I64 will force the rod 82 downwardly. At I65 in Fig. 2 I indicate a ball which is resiliently held in engagement with the notches I I66 of the ratchet 92 to serve as means for maintaining the lever 88 in the position to which it is ment 41 and hold the valve element 41 in lowered position such as shown in Fig. 5. The by-pass passage I61 has its inner end I68 in communication with the space 32 and its outer end H6 in communication with the vacuum space 5| in the valve housing 46. Theby-pass passage I61 crosses the bore. 8| and is obstructed by the rod 82 at all times except when the rod is lowered to such position that the groove I66 coincides with the passage I61 and thereby becomes a part of such passage, permitting a direct communication between the vacuum space 5| and the space 32. In Figs. 5 and 61 have shown the valve housing 46 separate from the head of the cylinder 26 so that the fluid passages from the valve 45 to the spaces 3| and 32 of the cylinder may be all clearly traced without reference to' several figures.

The operation of the device may be easily unv such times as the suction exerted in the space 5| from the intake I2 and through the conduit 53 is relatively low. At this time the groove 56 in the exterior of the valve elementfl is in a position connecting the annular spaces 56 and 6|. Through an opening I I2 in the wall forming the bottom of the groove 56 the suction at this time derstood from the following description. In Fig.

existing in the suction space 5| is communicated,

to the annular spaces 56 and 6|. This vacuum or suction communicated through the opening H2 is in turn communicated to the primary and secondary spaces 3| and. 32 of the cylinder 26 through the passage 58 which connects with the space 3| and through passages 62,64,and.6'| which connect the annular space 6| with the secondary 36, but the piston may be moved back and forth V r .by external application of force thereto. In Fig.

5 the piston is held 'at this time in leftward position by the spring 23, such leftward position corment 41 closes the annular space 6| through which vacuum communication with the space 32 was previously established as shown in Fig. 5.

Also the extreme lower end of the valve element 4'! now rests above the annular space 14, thus opening the space 32 of the cylinder 26 directly with the atmosphere through the short passage 15 and the opening I I3 through the rubber bumper 16 in the lower end of the valve housing 46.

' The annular groove in the exterior of the valve in the space 32 may pass freely through the pasmember 41 now connects the suction space with the annular space 56 so that the suction from the intake I2 is communicated only through the passage 58 to the primary space 3|, with the resuit that the piston 30 is quickly moved into the rightward position in which it is shown in Fig. 6, and the clutch pedal is swung in an anti-clockwise direction into: clutch-disengaging position. As long as the vacuum condition in thevacuum space 5| is maintained high enough to overcome the downward pressure of the spring 81, the valve element 41 will remain in raised position and the piston 30 will be held in rightward position with in the cylinder 26; therefore, as long as the engine is operated in a manner tocause a relatively high suction in the vacuum space. 5| the clutch of the automobile transmission willbe held in disengaged position, and during such time the gears of the transmission may be shifted and the vehicle itself may be moved by momentum or due to slope of the road, which is commonly termed free-wheeling.

The device may be actuated to permit the clutch of the vehicle to be engaged, merely by increasing the opening of the carburetor valve M, as by pressing inwardly on the pedal 16. The reduction in suction or vacuum condition resulting from this increased opening of the valve l4 permits the spring 81 to move the valve element 41 from the raised position in which it is shown in Fig. 6 to the lowered position in which it is shown in Fig. 5, the lower end of-the valve element 4! thenclosing the annular space 14 and the passage 15, and the groove 50 in the exterior of the valve element '4! connecting the annular spaces 56 and 6|.

.As a special feature of my invention the piston rod 35 has an inner or first annular recess 5 formed therein and an outer or second annular recess ||6 separated therefrom by a full-sized body portion l H. When the piston 30 is in rightward position as shown in Fig. 6, or at the beginning of its secondary or clutch-engaging movements, the space ||5-i-s positioned between the ends of the passages 62 and 64. Therefore, as soon as the valve element 41 is moved into lowered position, air is by-passed rapidly through the passage 64, the space I I5, the passage 62 and the space 6| tending to balance the gaseous pressure on each side of the piston. v The pull of the spring 23 may then move the piston rapidly in leftward or secondary direction for the reason that air sage 64, the space 5, the passage 62, to the annular space 6| which as shown in Fig. 5 is at this time in communication with the space 56, the suction space 5|, and the passage 58. This rapid leftward movement of the piston 30 continues until the full-sized portion of the piston rod 35 obstructs the adjacent ends of the passages 62 and thereby cuts off further escape of air from the space 32 through the passage 64. The only. escape of air that can now occur is through the passage 61 which is restricted by the valve 1|; therefore, during the time the portion obstructs the adjacent ends of the passages 62 and 64 a slow movement of the piston 30 is obtained by the controlled escape of air through the bypass passage 6'|. By adjustment of the extending length of the screw 38 the piston rod may be so.

positioned relative to the cylinder 26 that the of the passages 62 and 64 just prior to engagement of the friction parts of the automobile clutch, so that there will be a rapid moving of the clutch parts toward engaging position and a slow movement of the clutch parts immediately prior to and during the actual frictional or driving engagement thereof, thereby preventing all possibility of the clutch grabbing or operating jerkily.

After the clutch plates are fully engaged, the piston'rod 35 continues to move leftwardly, thus bringing the space ||6 into. position connecting the adjacent ends of the passages 62 and 64, so that thereafter a rapid movement of the clutch pedal is again had, to move the piston 30 into a position relieving any strains on the clutch parts, clutch pedal, or throw-out mechanism of the clutch.

I findthat the clutch-engaging movement of a a device of this character maybe very greatly improved, and it is a feature of my invention to provide such an improved action, by partly restricting the communication of the space 3| with the intake I2, so that pressure cannot be too quickly increased in the space 3| when the carburetor valve' M. is suddenly opened to full extent. This I accomplish by use of the opening 2 in the wall of the valve element 41, this opening 2 being interposed between the vacuum space 5| and the annular space 56 when the valve element 41 is in lowered position. With such a construction the rate of engagement of the clutch is a function of the manifold vaccum, which in a large measure determines the gaseous pressure Within the spaces 3| and 32. The manifold vacuum is in turn in a large part determined bythe mode of operation of the throttle. The spaces or compartments 3| and 32 are at all times, during the engagement of the clutch, in

communication with the manifold. Therefore, the gaseous pressure and thus the air densities within said compartments at any given instant during said engagement are a function of the degree of manifold vacuum.

In traveling down a hill I find that the increase in suction due to the engine being driven extreme position so as to, through the lever 88,

force the rod 82 down to extreme lowered position at which time the rod 82 will hold the valve element 41 in lowered or clutch-engaging position. At this time the clutch may be freely footoperated, and the annular groove I06 near the and the movement of the piston 30 will not be then influenced by movement of the enlarged portion II'I relative to the adjacent ends of the passages 62 and 64.'

' As shown in Fig. 7, it is a feature of my invention to connect the conduit 53 to the extreme lower end ofthe intake l2 and in a position adjacent the upwardly-swinging portion I25 of, the carburetor valve l4 so that immediately upon opening of the carburetor valve toward and through such a position as indicated by dotted lines I26, air from the interior as indicated by an arrow I 21 may enter the conduit 53 and break or lower the vacuum condition existing therein and thereby increasing the sensitiveness with which the clutch-operating device will respond to an opening of the carburetor valve I4.

I claim as my invention:

1. A clutch-operating device for a motor vehicle having a clutch and an internal combustion engine provided with an intake and a throttle, including: aclutch releaser attached to said clutch so'as to release same, said releaser including a movable means and a pair of'vacuumreceiving members placed so as to exert pulls on said movable means in opposite directions; means connecting the first of said vacuum members to said intake to actuate said first vacuum member continuously to exert a motivating force on said movable means in primary direction; a valve operable to open the second of said vacuum members to communication with said intake so as to balance said vacuum-members and permit move.- ment of said movable means in secondary direction; and a valve operated in accordance with 40 movement of said movable means for controlling the escape of fluid from said second vacuum member when said movable means moves in secondary direction.

2. A clutch-operating device for a motor vehi-' receiving members placed so as to exert pulls on said movable means inopposite directions; means connecting the first of said vacuum members to said intake to actuate said first vacuum member continuously to exert av motivating force on said movable means in primary direction; -a valve operable to open the second of said vacuum members to communication with said intake so as to balance said vacuum members and permit 'movement of said movable means in secondary direction; and a valve operated in accordance with movement of said movable means for controlling the escape of fluid from said second vacuum member when said movable means moves in secondary direction. I 4 3. A clutch-operating device for a' motor vehicle having a clutch and an internal combustion engine provided with an intake and a throttle, including: a clutch releaser attached to said clutch so as to release same, said releaser including a movable means and a pair of vacuumreceiving members placed'so as to exert pulls on said movable means in opposite directions; means connecting the first of said vacuum members to said intake to actuateesaid first vacuum member continuously to exert a motivating force on said movable means in primary direction; a valve operable to open the second of said vacuum members to communication with said intake so as to balance said vacuum members and permit movement of said movable means in secondary direction; and means for controlling the clutchclosing movement of said movable means including a fluid passage connecting with said second vacuum member for determining the speed at which fluid may discharge from said second vacuum member.

4. A clutch-operating device for a motor vehicle having a clutch and an internal combustion engine provided with an intake and a throttle, including: a clutch releaser attached to said clutch so as to release same; means connecting said releaser with said intake; and a valve operating in response to relatively high vacuum in said intake for closing communication of said connecting means to a part of said releaser and opening said releaser to atmosphere, to effect clutch-releasing actuation of said releaser.

5. A clutch-operating device for a motor vehicle having a clutch and an internal combustion engine provided with an intake and a throttle, including: a clutch releaser attached to said clutch so as to release same; means connecting said releaser with said intake; and a valve operating in response to relatively high vacuum in said intake for closing communication of said connecting means to a part of said releaser, to

effect clutch-releasing actuation of said releaser. 6. A clutch-operating device for a motor veengine provided with an intake and a throttle, including: a clutch releaser attached to said clutch so as to release same; means connecting said releaser with said intake; a valve for controlling communication of said connecting means to said releaser, to effect clutch releasing actuation of 'said releaser; resilient means normally holding said .valve in inoperative condition; and means selectively operable from the drivers seat of the vehicle to vary the tension of said resilient means.

7. A clutch-operating device for a motor vehicle having a clutch and an internal combustion hicle having a clutch and an internal combustion engine provided with an intake and a throttle, in-

cluding: a clutch releaser attached to said clutch so as to release same; means connecting said releaser with said intake; a valve operated by suction from said intake for controlling communication of said releaser-with said intake through said connecting means; resilient means normally holding said valve in inoperative condition; and means selectively operable from the drivers seat of the vehicle to vary the tension of said resilient means.

8. A clutch-operating device for a motor vehicle having a clutch and an internal combustion engine provided with an intake and a throttle, including: a clutch releaser attached to said clutch so as to release same; means connecting said releaser-with said intake;- avalve operated by suction from said intake for controlling communication of said releaser with said intake through-said connecting means; resilientmeans normally holding said valve in inoperative condition; and means selectively operable from the drivers seat of the vehicle to vary the tension of said resilient means and to maintain said valve in inoperative condition. i i

9. An automotive vehicle provided with an internal-combustion engine and a clutch, a fluid operated motor operably connected with the clutch, a control valve for said motor, a fluid transmitting 1 connection interconnecting the manifold of the engine and the control valve, and a spring within said valve acting against the action of the manifold vacuum, said valve being automatically actuated by the action of the vacuum to open the same and energize the fluid motor to disengage the clutch when and if the degree of gaseous pressure within the motor is equal to or exceeds a predetermined factor, and manually operable means for selectively adjusting the load of the valve spring or rendering said valve inoperative.

10. An automotive vehicle comprising an internal-combustion engine and a clutch, a doubleended fluid operatedmotor operably connected with said clutch, a control valve for said motor, a single fluid transmitting connection interconnecting the manifold of the engine and the control valve, a fluid transmitting connection interconnecting one end of the motor with the valve and a plurality of fluid transmitting connections interconnectingthe other end of the motor with said valve, the parts of said motor, the valve and the fluid connections being so constructed and arranged as to provide a suspended-in-vacuum type of motor, the clutchengaging operation of the motor effecting a variableengagement of the clutch to simulate manual operation of the same.

11. In an automotive vehicle provided with a clutch and an internal-combustion engine, a double-ended fluid motor for controlling the disengaging and engaging operations of the clutch, a control valve for said motor, fluid transmitting connections interconnecting the manifold of the engine, the valve and the motor, said fluid transmitting connections between the valve and motor being such that the valve,,when in one operative position, functions to intercommunicate the manifoldand motor to effect adisengagement of the clutch, and said connections further being such that, with the control valve in another of its operative positions, a certain amount of the fluid within one end of the motor is by-passed to the other end of the motor to thereby effect a controlled engagement of the clutch;

12. In an automotive vehicle provided with a clutch and an internal-combustion engine, 'a

double-ended fluid motor for controlling the distransmitting connections between the valve and,

motor being such that the valve, when in one operative position, functions to intercommunicate the manifold and motor to effect a disengagement of the clutch, and said connections further being such that, with the control valve'in another of its operative positions, a certain amount of the fluid within one end of the motor is by-passed to the other end of the motor to thereby effect a'controlled engagement of the clutch, said connections being further so constructed that the clutch engagement is effected in a plurality of distinct stages of movement, the slower of said stages being effected by a valve device determining the rate of flow of fluid through one of said connections.

13. An automotive vehicle provided with an internal-combustion engineand' a clutch; a doubleended fluid motor operably connected with the clutch, a control valve for said motor, an unimpeded fluidtransmitting connection interconnecting the manifold of the engine and one end of the motor, said valve being interposed in said connections interconnecting the other end of the motor with the valve, said valve functioning to alternately place the last mentioned end of the motor in circuit with the atmosphere and with the first mentioned end of the motor to thereby energize and deenergize the motor respectively to effect a disengagement and engagement of the clutch. 1'

14. An automotive vehicle provided with a clutch and an internal combustion engine having an intake manifold, p'ower means for controlling the engaging and disengaging operations of the clutch with operation of the internal combustion engine, said power means comprising a doubleended pressure differential operated motor, control valve means, and connections interconnecting said engine, motor and valve, said motor comprising means operative, when the valve means is operated to interconnect both ends of the motor with each other and with the manifold, to control the rate of engagement of the clutch in proportion tothe degree of gaseous pressure of the manifold.

15. In an automotive vehicle provided with a source of subatmospheric pressure and a clutch, power means for'operating the clutch comprising a double-ended pressure diiferential operated motor operably connected with the clutch, valve means for controlling the clutch disengaging and engaging operations of said motor and fluid transmitting connections interconnectingsaidsubatmospheric source, the valve means and the motor, said parts being so constructed and arranged that upon operation of the valve means to effect a clutch engaging operation of the motor both ends of the motor are placed in direct communication with the source of subatmospheric pressure.

16. An automotive vehicle provided with a clutch and an internal combustion engine having an intake manifold, power means for controllingthe engaging and disengaging'operations of the clutch with operation of the internal combustion engine, said power means comprising a doubleended pressure differential operated motor, control valve means, and connections interconnecting said engine, motor and valve, said motor comprising means operable, when the valve means.

power means for operating the clutch comprisw ing a double-ended pressure differential operated motor operably connected with the clutch, valve means for controlling the clutch disengaging and. engaging operations of said motor and fluid transmitting connections interconnecting said subatmospheric source, the valve means and the motor, said parts being so constructed and arranged that upon operation of the valve means to effect-a clutch engaging operation of the motor both ends of'the motor are placed in direct communication with the source of subatmospheric end of the motor is connected with the atmos- 'phere.

cLIr'roN R. ROCHE. 

